This invention relates to an interface device, an interface method in order to control an object to be controlled by making use of brain activities of a subject and a control training device by the use of the interface device.
Recently, researches on brain-computer interface (hereinafter called BCI) that detects nervous activities of brain and controls various devices through a computer (an interface device) have actively been conducted. In accordance with a conventional study, in order to actualize the researches, a computer (an interface device) comprehends direct thinking of a subject, for example, thinking to move to the right, by means of detecting a signal from the brain of the subject and actually controls a device to move to the right. (patent publication number 2000-172407)
A brief summary of brain researches by means of measuring brain activities will be explained below by the use of FIG. 7 wherein brain function is simplified.
In FIG. 7, each of “A”, “B” and “C” is a time and space pattern which the brain expresses respectively. This is called “representation”. In order to measure the representation (practically, a part of the representation) noninvasively, there are brain activity measuring devices by the use of fMRI, near-infrared lights, MEG, EEG or ECoG (electrocorticogram).
However, it is not possible to comprehend brain activities just by the use of brain patterns measured by the brain activity measuring devices. Because there might exist unexplained “X” lying behind the brain patterns and the “X” might be an origin of each pattern or there is no knowing how many and what kind of pattern should be assumed. Furthermore, it is not easy to arrange measured data of the brain researches by means of brain activity measuring devices. Additionally, since “B” includes great variety of expressions, the brain researches are intricate.
Then take “move a wheelchair to the right” by the use of BCI for example. In case that a red button for moving the wheelchair to the right is equipped, four steps are required; (1) measure the brain, (2) interpret an intension (direct thinking) of “move to the right” based on the measured data, (3) translate the intension into a motion to push the red button, and (4) output a signal to the button. Among them, in order to interpret (2) and to translate (3), profound knowledge of brain science is required. More specifically, it is not possible comprehend how “a right direction viewed from the body”, “move”, or “push the red button” is expressed in the brain with consideration given to the unexplained “X”. Furthermore, in measuring the brain as (1), since it is not clear which part is to be measured and how to measure, there is no choice but to measure a broader area as much as possible and as many portions as possible.
As mentioned above, an approach to comprehend direct thinking of a subject by a computer (an interface device) has no choice but to wait further developments of brain activity researches and it is a situation that an early realization of the BCI technology is difficult.